That's about the only question that goes unanswered — but not unjoked about — in X-Men: First Class, the reboot of the classic Marvel Comics story about mutated humans at war with each other and the rest of mankind.

Directed by Matthew Vaughn, X-Men: First Class is a tale both humorous and heartbreaking at the same time. As fans witness the genesis and budding friendship of mutants Charles Xavier (James McAvoy) and Erik Lehnsherr, a.k.a. Magneto (Michael Fassbender), it's impossible to put their dark fates out of mind.

Equally difficult to ignore is whether McAvoy and Fassbender have surpassed their far-more-decorated predecessors (Patrick Stewart and Ian McKellen) in both chemistry and acting chops.

But first back to the story. It turns out that all it took to create the not-so-merry band of X-Men was a little fracas called the Cuban Missile Crisis, an opportunity to give J.F.K. a little more face time at the cineplex as well as giving the Cold War a new yarn to spin.

As X-Men: First Class tells the story, a former WWII concentration camp doctor/mutant named Shaw (played deliciously evil by Kevin Bacon) is in fact responsible — not Nikita Khrushchev — for nearly triggering WWIII. But what's really bad for Shaw is that Lehnsherr — the subject of his most sadistic experiments at the camp as a child — survived and is fighting with the good guys (for now).

Magneto's power — born of the agony of seeing his parents murdered by Nazis — is peacefully corralled by the calm, clairvoyant Xavier, played a bit too much like Austin Powers at times by McAvoy. ("Groovy, baby!") Still, it's only a matter of time until the chance for vengeance overwhelms Lehnsherr, setting the stage for a future of mutants fighting each other as well as lesser-evolved minds in government.

Previous comic reboots have benefited from exceptional performances by supporting cast members — Jack Nicholson in 1989's Batman, Heath Ledger in The Dark Knight, Zachary Quinto in Star Trek. There's no shortage of skill in X-Men: First Class. Jennifer Lawrence is a stunner as a young Raven/Mystique, who struggles to embrace her all-blue physique. And January Jones' screen time is too brief as the telepathic Emma Frost, whose chilly demeanor is matched only by a diamond-frosted exterior.

A menagerie of other mutants makes up the remaining cast — including Beast (Nicholas Hoult), Riptide (Álex González) and Banshee (Caleb Landry Jones) — each deserving of a longer version of their stories.

Ultimately, though, this is a story about Xavier and Magneto, and McAvoy and Fassbender do not disappoint. The scenes of their recruitment of fellow mutants is priceless, imparting a rollicking Ocean's Eleven feel (and including a nifty cameo in the process). But the fun can't last forever — "Peace was never an option," Magneto concedes — and while a nuclear war is avoided, their separate fates are assured.

For Magneto, it means a life on the run in the company of mutant criminals. For Xavier, it's life in a wheelchair . . . without the company of his friend. And without his hair. But that's a story for another movie.